This would have been unheard-of a few years ago, as wireless carriers hated VoIP companies like Skype.

Why? Because VoIP was believed to threaten phone companies' core businesses by moving more phone calls -- especially international long-distance -- to the Internet, versus vastly more expensive phone networks.

But the damage has been done.

And wireless companies are finding their growth selling mobile data service, not mobile voice service, and have recently significantly cut the fees for unlimited calling. More VoIP services like Google Voice have sprung up, and as adoption increases, phone companies won't be able to fight them for much longer.

Plus, even if you use Skype for all your calls, you still have to buy a calling plan to get a cheap, subsidized smartphone. So wireless carriers don't have much to lose after all.